The present invention relates to a new and improved construction of a hydrostatic support arrangement or device which is of the type comprising a pressure chamber for a pressurized fluid medium and a bearing surface which is pressed against a part to be borne or supported by the pressure of the pressurized fluid medium which is effective in the pressure chamber, this pressure in turn bearing against a support member.
A hydrostatic support arrangement of this type is known, for instance, from U.S. Pat. No. 3,119,324 or British Pat. No. 611,466, the disclosure of which is incorporated herein by reference. In these prior art constructions the pressure chamber is formed in a cylinder within which there is guided a piston. The piston is provided with a bearing pad or the like upon which there is formed the bearing surface. In both cases the support device or arrangement is secured to a stationary support member around which there can rotate a hollow tubular roll shell or barrel. The roll shell is hydrostatically supported by a number of support devices, so that the shape of the roll shell remains uneffected by the support member sagging under load. Rolls of this type are used, for example, in papermaking machinery and for textile processes and are typically known in the art as flexure adjusting or controlled deflection rolls. With such type rolls, upon rotation of the roll shell about the support member, there is formed a hydrodynamic film of lubricant from an oil bath in the roll shell between the bearing surfaces of the support devices and the inside surface of the roll shell. A drawback of such state-of-the-art constructions is that they are mechanically fairly complex.
Furthermore, in U.S. Pat. No. 3,802,044 and German patent publication No. 2,230,139, there is disclosed another support device or support arrangement for a controlled deflection roll wherein the bearing surface is formed on a punch or prop-like member which is guided for pivoting and axial movement relative to the support member. The bearing surface is equipped with at least one bearing pocket for the hydrostatic mounting of the member or part to be borne or supported by the support device, such member in this case being constituted by the roll shell. The bearing pocket or pockets communicate by means of throttle bores or restrictor passages with the cylinder chamber of the support device. This construction enables a hydrostatic lubricant film to form between the bearing surface and the supported member, i.e. the roll shell.
This heretofore known construction has proved to be very satisfactory and affords many advantages, for instance, a large stroke of the punch or prop-like member, so that in many instances it is possible to avoid the use of external contact or pressing mechanisms, which otherwise are required in the case of controlled deflection rolls. Yet, this conventional construction is too elaborate for many simple applications.